1. Field of Invention
The present invention relates to a benzoxazine compound and a preparation method for the benzoxazine compound. More particularly, the present invention relates to a phosphorus-based oxazine compound and a preparation method of the phosphorus-based oxazine compound.
2. Description of Related Art
Although the latest developed benzoxazine resin may be classified as one kind of phenolic resin, it actually is quite different from the conventional phenolic resin. The benzoxazine resin affords high glass transition temperature (Tg), high modulus, low moist absorption rate, excellent electrical characteristics, and high charyield. Moreover, there are more advantages for the benzoxazine resins, including no need for highly acidic catalysts and no byproducts during curing, the ring-opening curing after heating the monomer, and almost no voluminal variations after curing.
So far, the most commonly used benzoxazine compounds can be categorized as B-m type and B-a type compounds. The B-m type compounds are synthesized from bisphenol A, formaldehyde and methylamines, while the B-a type compounds are synthesized from bisphenol A, formaldehyde and aniline. The preparation methods for synthesizing the B-m type and the B-a type compounds are shown as follows:

Based on the published papers, the benzoxazine compounds were synthesized from bisphenol A, formaldehyde and amines with mono-functional groups. If the benzoxazine compounds were synthesized from the amines with bi-functional groups, formaldehyde and phenols with mono-functional groups, large insoluble molecules of high molecular weights would form. It is because the functional group —NCH2OH would have condensation reaction with the amino group of aniline, and —NCH2OH would have dehydration reaction with the para- or ortho-hydrogen of aniline to form high molecular weight insolubles. Due to the formation of high molecular weight insolubles, the synthesized benzoxazine compounds come up with inferior purity and low yield rates.
Moreover, the fire-resistant characteristics of the benzoxazine resins, though superior to those of the conventional phenolic resins, can be further improved for extensive applications.